This invention relates to a tomographic X-ray apparatus for the production of transverse layer images of an exposed object, consisting of a patient's support, an X-ray measuring arrangement with an X-ray source, which generates a bundle of X-rays penetrating the exposed object and of which the cross sectional extent perpendicular to the plane of the layer is equal to the thickness of the layer, for example, and a radiation receiver which ascertains the radiation intensity beyond the object by scanning the projected bundle of rays, and a driving device for the measuring arrangement including a pivot mounting for accommodating rotational movements of the X-ray measuring arrangement, the apparatus further including a measurand converter for the conversion of the signal supplied by the radiation receiver into a tomographic image.
For detecting the layer image, the rotational movements may take place through equidistant angular amounts, each in alternating sequence with a displacement of the measuring arrangement along a straight line perpendicular to the central ray of the bundle of X-rays, when a single detector is used as the radiation receiver. Alternatively, it is possible to dispense with the displacements along a straight line path if the radiation receiver is built up of a multiplicity of ray detectors whose signals are simultaneously processed by the measurand converter. For example, the X-ray beam may be fan-shaped and the detectors may be arranged in succession so as to simultaneously receive the X-ray energy after traverse of paths of equal length.
A tomographic X-ray apparatus of this kind is described in U.S. Pat. No. 3,974,388 issued Aug. 10, 1976.